Coreopsis rosea

Taisha is both the photographer and writer for today’s entry (photos are from last autumn). She writes:

Coreopsis rosea, or the pink tickseed, is a perennial species in the Asteraceae. This taxon is found on sandy shores or marsh edges of coastal eastern North America, in three disjunct groupings: 1) Nova Scotia, Canada; 2) Massachusetts to Delaware, USA; and 3) South Carolina & Georgia, USA. It is also an ornamental species of gardens. Plants bear composite inflorescences, with pink (to white) ray flowers surrounding yellow disc florets. Stems are 10-60 cm in height and lined with a series of oppositely-arranged linear-lanceolate leaves. The dry fruits (cypselae) are oblong without wings or pappi (modified calyces).

The pink tickseed is globally rare. In Canada, it is a federally endangered species (latest assessment: 2013), occurring only at the northern limit of the plant community termed the Atlantic Coastal Plain Flora (ACPF) (a region which extends south to Florida). This floral group is threatened mainly due to habitat loss along the American eastern seaboard and adjacent Canada. In Nova Scotia, dams are of particular concern, as their placement often corresponds with watershed lakes that serve as habitat for species of the ACPF. Over half of the most important shorelines on watershed lakes in Nova Scotia have been lost as ACPF habitat. As Coreopsis rosea is at its northernmost limit in Nova Scotia, it is thought that length of growing season may be a determining factor for its distribution and abundance, as well as other species in the community.

In a study by Lusk & Reekie from the Acadia University Department of Biology, the researchers sought to test the effects of length of growing season (particularly with respect to hydrology and flooded conditions) on species from the ACPF including Coreopsis rosea. The hope was to gain a better understanding of the limiting variables affecting this group to better manage and maintain the plant community.

Beginning at the end of June 2004, Lusk & Reekie transplanted Coreopsis rosea (along with Hydrocotyle umbellata) at three lakes with different hydrological regimes within southwestern Nova Scotia’s Tusket River system. The transplants were planted at several depths on three different occasions using four week intervals. The researchers visited the plants every two weeks, only ceasing over the winter months. Water levels, plant survival, flowering, and plant growth were measured, observed and recorded. At the end of August 2005, the transplants were harvested, dried, and weighed. It was found that transplant date and depth both affected the biomass and flowering of Coreopsis rosea with results varying at each of the lakes. In general, transplants planted higher on the shoreline and earlier in the year were both larger and more copiously flowering than those planted lower along the lakeshores or later in the year.

With this information, Lusk & Reekie suggested that dam reservoirs can provide appropriate habitat for certain Coastal Plain species if water levels are managed. They proposed that lowering water levels of reservoirs in the spring and during times of high precipitation would increase growing season and decrease flood stress. The authors also suggested to raise water levels in the autumn to prevent cold damage. Lastly, the researchers suggested their study can be used to address gaps in the ACPF recovery plan (PDF), in order to better help protect and conserve at-risk species within this group (see: Lusk, J, and EG Reekie. 2007. The effect of growing season length and water level fluctuations on growth and survival of two rare species and at risk Atlantic Coastal Plain flora species, Coreopsis rosea and Hydroctyle umbellata. Canadian Journal of Botany. 85(2):119-131).

Coreopsis rosea
Coreopsis rosea

11 responses to “Coreopsis rosea”

  1. Peony Fan

    Lovely photos, especially the upper one where the photographer probably had to crouch way down…thanks. I am glad to hear that people are doing research that can help minimize the damage done by dams to the surrounding habitat.

  2. Lindelani

    Lovely picture. It looks like our indigenous Felicia fruticosa subsp. fruticosa

  3. Souren Ala

    Looks a lot like Cosmos bipinnatus too

  4. Jessica

    That’s lovely.
    I’ve seen this plant pretty regularly at nurseries and in catalogs. I didn’t realize it was a native. Makes me love it even more.


    Lovely photos and info!
    Thank you!

  6. billbarnes

    More importantly than knowing that they will survive being transplanted to specific cites , is the question as to whether they will reproduce and establish new colonies via seed and are appropriate pollinators in the offering . I would hope the work continues

  7. Wendy Cutler

    I’m really enjoying Taisha’s postings. Do we get to keep her?

  8. Daniel Mosquin

    Wendy, I don’t have all of the information I need in front of me to know. For my part, the application for the summertime UBC-subsidized Work-Learn position has gone in, but I won’t know the results for a little while yet. She has been a treasure.

  9. elizabeth a airhart

    lovely pink flowers for my eyes and fine write up lucky us
    leave me to blossomwhere i sprung
    a joy untarnished shall i seem
    pluck me,and you dispel the charm
    and blur the dream
    f l coates
    thank you daniel more then once

  10. Wendy Cutler

    Elizabeth, I’ve been thinking about you lately, how I haven’t seen your name in ages (though I see you did post a comment a few days ago). I’m glad you’re back.

  11. elizabeth a airhart

    thank you wendy i have missed you all
    the computer still iffy but mainly its been me being very iffy
    elizabeth florida usa

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